Differentiating among Gas Mixtures Using a Single Tin Oxide Gas Sensor

2014 ◽  
Vol 605 ◽  
pp. 189-193 ◽  
Author(s):  
Faramarz Hossein-Babaei ◽  
Amir Amini ◽  
Khachik Babaians
Keyword(s):  
Gas Sensor ◽  
Tin Oxide ◽  
Three Dimensional ◽  
Feature Space ◽  
Gas Mixtures ◽  
Response Patterns ◽  
Diagnostic Features ◽  
Resistive Gas Sensors ◽  
The Individual ◽  
Different Gases

Despite all their positive features oxide-based resistive gas sensors are nonselective and respond similarly for different gas and gas mixtures. The authors have recently demonstrated that the response patterns generated by a generic tin oxide gas sensor induced by thermal shocks contain considerable amounts of information regarding the nature of the present gas. Here, the results of using a similar technique on different two-component gas mixtures are reported. The gas mixtures are (1-butanol)x(2-butanol)1-x, (1-propanol)x(2-butanol)1-x, (1-butanol)x(1-propanol)1-x, and (1-butanol)0.33(2-butanol)0.33, (1-propanol)0.33, each at various total concentrations. The diagnostic features of the response patterns were extracted, by applying wavelet transform, and used for their discrimination in a three dimensional feature space. The positions of the clusters related to different gases are consistent with their composition and facilitate estimating the individual concentrations of the components.

Drift-Like Terms Minimization in the Responses of a Generic Tin Oxide Gas Sensor

2014 ◽  
Vol 605 ◽  
pp. 511-514 ◽  
Author(s):  
Amir Amini ◽  
Pejman Shabani ◽  
Mohsen Gharesi
Keyword(s):  
Gas Sensor ◽  
Tin Oxide ◽  
Feature Space ◽  
Training Data ◽  
Temperature Modulation ◽  
Response Patterns ◽  
Environmental Sensors ◽  
Humidity Level ◽  
Ambient Humidity ◽  
Virtual Array

The responses of a tin oxide gas sensor vary with humidity level in the surrounding atmosphere. Such response variations can cause error in the estimation of the concentration level of the target gas and need compensation measures. Different methods have been used to compensate the effect of humidity, which usually require utilization of other parallel environmental sensors and costly data fusion methodology. Particularly, such a drift alters the response patterns obtained from a real or virtual sensor array and hinders gas recognition. Here, we report response patterns recorded from a virtual array made by operating temperature modulation at different ambient humidity levels for three different target gases. Humidity level varied from 30-70% and response patterns were recorded for methanol, ethanol and 1-propanol at a wide concentration range. It is shown that by utilizing the thermal shock-induction method for the temperature modulation of the sensor, the drift levels are low, and with a single set of training data collected at RH=50%, responses obtained in the whole humidity range can be discriminated from each other. The clusters volumes in the feature space grow with the span of the ambient humidity variations, but they remain separate allowing gas recognition.

Semi-automated methods for 3-D reconstruction of macromolecular complexes

1995 ◽  
Vol 53 ◽  
pp. 42-43
Author(s):  
B. Carragher ◽  
M. Whittaker
Keyword(s):  
Three Dimensional ◽  
Time Saving ◽  
Macromolecular Complexes ◽  
Symmetry Properties ◽  
Dimensional Reconstruction ◽  
Experienced Operator ◽  
Projection Images ◽  
The Individual ◽  
Natural Symmetry

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.

Biotemplated facile synthesis of three‐dimensional micro/nanoporous tin oxide: improving the flammable and mechanical properties of flexible PVC

2019 ◽  
Vol 14 (8) ◽  
pp. 828-830 ◽  
Author(s):  
Weihua Meng ◽  
Weihong Wu ◽  
Weiwei Zhang ◽  
Luyao Cheng ◽  
Yunhong Jiao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tin Oxide ◽  
Three Dimensional ◽  
Facile Synthesis

Phonetic iconicity in the evaluative morphology of a sample of Indo-European, Niger-Congo and Austronesian languages

2010 ◽  
Vol 3 (2) ◽  
pp. 156-180 ◽  
Author(s):  
Renáta Gregová ◽  
Lívia Körtvélyessy ◽  
Július Zimmermann
Keyword(s):  
Three Dimensional ◽  
Sound Symbolism ◽  
Three Dimensional Model ◽  
Austronesian Languages ◽  
Place Of Articulation ◽  
European Languages ◽  
Phonetic Symbolism ◽  
The Individual ◽  
Core Vocabulary

Universals Archive (Universal #1926) indicates a universal tendency for sound symbolism in reference to the expression of diminutives and augmentatives. The research ( Štekauer et al. 2009 ) carried out on European languages has not proved the tendency at all. Therefore, our research was extended to cover three language families – Indo-European, Niger-Congo and Austronesian. A three-step analysis examining different aspects of phonetic symbolism was carried out on a core vocabulary of 35 lexical items. A research sample was selected out of 60 languages. The evaluative markers were analyzed according to both phonetic classification of vowels and consonants and Ultan's and Niewenhuis' conclusions on the dominance of palatal and post-alveolar consonants in diminutive markers. Finally, the data obtained in our sample languages was evaluated by means of a three-dimensional model illustrating the place of articulation of the individual segments.

Distribution, systematics and nomenclature of the three taxa of Common Stonechats (Aves, Passeriformes, Muscicapidae, Saxicola) that breed in the Caucasian region

2020 ◽  
Vol 29 (1) ◽  
pp. 33-57
Author(s):  
V.M. Loskot ◽  
G.B. Bakhtadze
Keyword(s):  
Geographic Distribution ◽  
Habitat Preferences ◽  
Junior Synonym ◽  
Type Locality ◽  
Diagnostic Features ◽  
Western Turkey ◽  
Geographical Variations ◽  
History Of ◽  
The Individual ◽  
North Western

Geographic distribution and habitat preferences of Saxicola rubicola rubicola (Linnaeus, 1766), S. maurus variegatus (S.G. Gmelin, 1774), and S. m. armenicus (Stegman, 1935) inhabiting the Caucasian Isthmus and adjacent areas are described in detail. We examined the individual, sexual, age, seasonal and geographical variations of seven main diagnostic features of both plumage and morphometrics (exactly, the length of wing and tail) using 381 skin specimens. Substantially improved diagnoses of S. m. variegatus and S. m. armenicus are provided. After a thorough examination of the materials and history of the expedition of Samuel Gmelin in 1768–1774, and his description of Parus variegatus, it was concluded that the type locality of this taxon was the vicinity of Shamakhi in Azerbaijan not Enzeli in North-Western Turkey. It is also shown the fallacy of the recently proposed attribution of the holotype of the northern subspecies S. m. variegatus to the southern taxon S. m. armenicus and synonymisation of these names, as well as the replacement of the name S. m. variegatus by its junior synonym S. m. hemrichii Ehrenberg, 1833 for the northern subspecies.

scholarly journals A branch & bound algorithm to determine optimal bivariate splits for oblique decision tree induction

2021 ◽  
Author(s):  
Ferdinand Bollwein ◽  
Stephan Westphal
Keyword(s):  
Decision Tree ◽  
Feature Space ◽  
Classification Problems ◽  
Decision Tree Induction ◽  
Single Attribute ◽  
Global Optimal ◽  
The Individual ◽  
Tree Building ◽  
Very High ◽  
Multiclass Classification Problems

AbstractUnivariate decision tree induction methods for multiclass classification problems such as CART, C4.5 and ID3 continue to be very popular in the context of machine learning due to their major benefit of being easy to interpret. However, as these trees only consider a single attribute per node, they often get quite large which lowers their explanatory value. Oblique decision tree building algorithms, which divide the feature space by multidimensional hyperplanes, often produce much smaller trees but the individual splits are hard to interpret. Moreover, the effort of finding optimal oblique splits is very high such that heuristics have to be applied to determine local optimal solutions. In this work, we introduce an effective branch and bound procedure to determine global optimal bivariate oblique splits for concave impurity measures. Decision trees based on these bivariate oblique splits remain fairly interpretable due to the restriction to two attributes per split. The resulting trees are significantly smaller and more accurate than their univariate counterparts due to their ability of adapting better to the underlying data and capturing interactions of attribute pairs. Moreover, our evaluation shows that our algorithm even outperforms algorithms based on heuristically obtained multivariate oblique splits despite the fact that we are focusing on two attributes only.

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